Microscopic dynamics in liquid GeO 2

We investigate liquid ${\mathrm{GeO}}_{2}$ with inelastic neutron scattering at temperatures up to two times the glass transition temperature ${T}_{g}.$ Structural relaxation is still too slow to be resolved by the instrumental resolution. The inelastic spectra reveal a pronounced peak at 3 meV. The position of the peak maximum shows no dispersion in wave number q. Over the full-energy range spectra scale with the Bose occupation as expected for harmonic vibrations. For energies below $\ensuremath{\simeq}2 \mathrm{meV}$ the dynamic susceptibility shows a linear energy dependence that can be attributed to harmonic acousticlike excitations. There is no indication for a fast \ensuremath{\beta}-relaxation process as predicted by mode coupling theory.